In excess of two billion one liter packages of motor oil are sold annually in the United States alone. Therefore, improvements to the packaging of motor oil and other automotive fluids can be of significant concern to the automotive industry, the packaging industry and consumers.
Blow-molded plastic containers for automotive fluids are available in a variety of shapes and are normally made from high density polyethylene in an extrusion blow-molding process. Some of these containers are designed to have substantially rectangular footprints so that they may be stacked and shipped on standard sized shipping pallets.
An example of a one liter container for automotive fluids is disclosed in U.S. Pat. No. 4,877,142 issued on Oct. 31, 1989 to Doering and assigned to Texaco. The Texaco container has a substantially rectangular footprint for efficient packing and shipping, and has an offset spout which facilitates pouring. Surveys have indicated that this style of container is received favorably by consumers.
A significant portion of the cost to manufacture blow molded containers is in the plastic required to make the containers. For instance, the referenced Texaco container requires about 51 grams of HDPE.
Significant savings can be achieved by reducing the amount of plastic required to make each container. As an example, assume that HDPE is sold at approximately 40 cents/pound (0.00088 cents/gram), that a reduction of three grams of plastic per container can be achieved, and that 100 million containers are to be produced for a given year. The reduction of as little as three grams of HDPE per container would result in a savings of $300,000.00.
The degree of container rigidity required for packing and shipping purposes prevents manufacturers from reducing the amount of plastic in the manufacture of containers. Filled containers are packed in bulk in cardboard boxes, or plastic wrap, or both, and placed on shipping pallets. A bottom row of packed, filled containers may support several upper tiers of filled containers, and potentially, several upper boxes of filled containers. The lowermost containers in the stock must be sufficiently rigid to resist distortion under these packing and shipping conditions.
The rigidity of containers is measured by compression tests and is referred to as top loading capability. For instance, the referenced one liter Texaco container manufactured from 51 grams of HDPE has a top loading capability of about 45 to 50 pounds. A reduction of plastic in the container would be expected to result in a decrease in top loading capability. Thus, for every container configuration, a balance must be achieved between minimizing the amount of plastic for cost saving purposes while providing a sufficient amount of plastic to provide container rigidity.
Although the referenced Texaco container functions satisfactorily for its intended purposes, there is a need for a blow-molded plastic container which is similar in configuration, but which is capable of being manufactured from less plastic while having increased rigidity. A one liter version of the container should be capable of being manufactured from less than about 48 grams of HDPE to provide a cost savings of three grams per container, and it should provide a minimum of 50 pounds top loading capability.